The Trump presidency has generated new concern about democratic backsliding in the United States. In response, observers have pointed to the institutions of federalism and state level governance as protectors of democratic institutions. This chapter, however, suggests that state governments have been central to democratic backsliding in the United States in the contemporary period. I develop a set of new time-series measures of democratic performance in the U.S. states based on over 100 indicators of state performance in areas such as voting rights, gerrymandering, and racial inequality, analogous to cross-national measures of democracy used by scholars of comparative politics. The measures allow me to test competing theories about the role of party, partisan competition, and polarization in the expansion and contraction of democracy in the contemporary period. Competition and polarization in state party systems are modestly related to democratic performance, but, above all, Republican control of state government reduces democratic performance. This result emphasizes the racial, geographic, and group-based incentives in the modern GOP, and calls into question theories focused on party competition and polarization within states. The racial, geographic, and elite incentives of the national Republican coalition may instead determine the health of democracy in the states.